The present invention relates to a cleaning apparatus which cleans a cylinder in a transfer device (coating device/printing device) which performs transfer (coating/printing) on a transfer target body (sheet/web).
A conventional printing apparatus comprises a printing unit which prints a sheet fed from a feeder, a coater cylinder which coats the sheet printed by the printing unit, and a varnish roller which transfers varnish onto the coater cylinder. In a conventional cleaning apparatus in the printing apparatus having the above arrangement, as disclosed in Japanese Patent Laid-Open No. 2000-289190, immediately before a sheet that precedes the final sheet to be fed from the printing unit by a predetermined number is fed to the coater cylinder, the varnish roller is thrown off from the coater cylinder. After that, the coater cylinder is thrown on (brought into contact with) an impression cylinder and a predetermined number of sheets are fed, so the varnish attached to the circumferential surface of the coater cylinder is transferred to the sheet, thus cleaning the circumferential surface of the coater cylinder.
The conventional cleaning apparatus described above performs so-called “cleaning by printing” in which the varnish attached to the circumferential surface of the coater cylinder is transferred to the sheet, thus cleaning the coater cylinder. This accompanies wasted paper and increases the cost particularly when the sheet is expensive. It also requires the operation of removing the cleaning waste paper stacked on the delivery pile, increasing the load to the operator.